Ulceration of skin on a patient's feet is a common complication of diabetes and peripheral vascular disease. Ulcers can become so serious as to necessitate amputation. Ulcers can occur on any part of the foot, but the bony prominences of the heels and the ankles are especially vulnerable for a bed-ridden patient. The ulcers result in decreased pain sensation which can cause abnormal loading of the feet, increased localized pressure and formation of callouses, which cause tissue damage. The ulcers are primarily treated by ensuring an adequate blood supply; treating the underlying infection with appropriate antibioics; and by relieving the pressure on the affected part.
Pressure ulcers (also known as bed sores) often develop in individuals confined for an extended period to a particular position in a bed or chair. The pressure ulcers can be treated by managing tissue loads, including direct pressure, friction, and shear, through positioning techniques and use of appropriate support surfaces. For example, positioning devices can be used to raise a heel ulcer off the support surface and prevent direct contact between the surface and bony prominences. Past solutions include padding the heel area. But this is often ineffective because the pressure between the padding and the heel may remain significant enough to still cause ulceration, and, moreover, padding will reduce circulation of air about the heel which normally aids in healing of ulcers.
Another conventional means for reducing heel pressure is using a foot and leg protector having a rigid outer shell with an inner soft protective liner. However, the protector includes wrapping or adjusting straps which may cause added pressures on the skin, and reduce blood flow. Additionally, the user has to move, adjust or remove the straps frequently which is inconvenient, uncomfortable and may not be possible for a seriously disabled patient.
Protective devices without straps include a pressure resilient cushion that is adapted to be positioned under a bony prominence (including the knee joint or heel). The pad includes a relatively flat surface conformable to the skin area which it protects. The pad preferably includes a recess to surround the bony prominence, and a section around the recess that abuts, supports and cushions the region around the prominence. However such pads do not maintain the prominence of ankle, heel and elbow at a sufficiently elevated position and, again, significant pressure against the heel may remain when the pad is employed.
Surrounding the limb with a cylindrical padding, or placing a cushion under the calf does elevate the limb. But a cushion does not roll when the patient does so in bed. While cylindrical padding can roll with the patient, it cannot stabilize the limb when the bed surface suddenly deforms (such as by the plaintiff moving his other leg or limbs, or resting an object on or someone suddenly sitting on the bed).
Therefore, there is a need for a device to reduce pressure at the bony prominences of heels, ankles and elbows, which can move with the patient in bed and stabilize the limbs against the bed surface moving.